Integrated mems microphone performance enhancement with a membrane

Abstract

Systems and methods for a MEMS microphone package are disclosed. The MEMS microphone package may include a first port to direct sound to a MEMS system, including a die substrate, an acoustic membrane, and one or more plates. The MEMS microphone package may include an ASIC to produce microphone output based on an electrical signal, a PCB, a lid, and a second port. The first port and the second port may define a front volume and a back volume respectively. The second port may increase the back volume to improve sensitivity and reduce the acoustic sensor's noise floor to improve signal-to-noise ratio.

What is claimed: 
     
         1 . A microphone system comprising:
 a printed circuit board (PCB);   an application-specific integrated circuit (ASIC) attached to the PCB, wherein the ASIC produces a microphone output from an electrical signal;   a micro-electromechanical systems (MEMS) component attached to the PCB, wherein the MEMS component comprises a plate, an acoustic sensor, and a MEMS die substrate, and wherein a front volume of air is formed between the PCB and the acoustic sensor;   a lid secured to the PCB, wherein the lid forms a back volume of air around the ASIC and the MEMS component;   a first port formed in the PCB, wherein the first port is positioned to direct sound waves, through the front volume, toward the acoustic sensor; and   a second port formed in the lid to increase air volume into the back volume.   
     
     
         2 . The microphone system of  claim 1 , wherein the acoustic sensor comprises an acoustic membrane that vibrates in response to the directed sound waves. 
     
     
         3 . The microphone system of  claim 1 , further comprising a membrane covering the second port, wherein the membrane blocks at least one of: debris, foreign material, water ingress, or particulate matter from passing through the second port. 
     
     
         4 . The microphone system of  claim 1 , further comprising an enclosure forming a third air volume surrounding the lid and the PCB. 
     
     
         5 . The microphone system of  claim 4 , wherein the enclosure comprises an opening to direct sound waves toward the first port. 
     
     
         6 . The microphone system of  claim 5 , further comprising a mesh positioned between the opening of the enclosure and the second port, wherein the mesh blocks at least one of: debris, foreign material, water ingress, or particulate matter from passing through the second port into the front volume. 
     
     
         7 . The microphone system of  claim 1 , wherein a material covers at least one of the first port and the second port. 
     
     
         8 . The microphone system of  claim 7 , wherein the material is an expanded polytetrafluoroethylene membrane. 
     
     
         9 . The microphone system of  claim 1 , wherein air volume through the second port and into the back volume increases at least one of a sensitivity or a signal-to-noise ratio (SNR) of the MEMS component. 
     
     
         10 . The microphone system of  claim 1 , wherein the microphone system is incorporated into a device, wherein the device is at least one of: a desktop computer, a notebook computer, a laptop computer, a netbook, a tablet computer, an e-book reader, a Global Positioning System (GPS) device, a camera, a personal digital assistant (PDA), a handheld electronic device, a cellular telephone, a smartphone, a head-mounted device, an augmented reality device, a virtual reality device, a smart watch, or a charging case. 
     
     
         11 . A method to form a microphone system, comprising:
 attaching an application-specific integrated circuit (ASIC) to a printed circuit board (PCB);   attaching a micro-electromechanical systems (MEMS) component to the PCB, wherein the MEMS component comprises a plate, an acoustic sensor, and a MEMS die substrate, and wherein a front volume of air is formed between the PCB and the acoustic sensor;   securing a lid to the PCB to form a back volume of air around the ASIC and the MEMS component;   directing sound waves, through the front volume, toward the acoustic sensor, wherein the sound waves are directed via a first port in the PCB;   increasing air volume into the back volume via a second port formed in the lid; and   producing, via the ASIC, a microphone output via an electric signal.   
     
     
         12 . The method of  claim 11 , further comprising:
 vibrating an acoustic membrane positioned within the front volume, in front of the acoustic sensor, in response to the directed sound waves.   
     
     
         13 . The method of  claim 11 , further comprising:
 covering the first port with a first membrane and covering the second port with a second membrane.   
     
     
         14 . The method of  claim 13 , wherein at least one of the first membrane or the second membrane is an expanded polytetrafluoroethylene material. 
     
     
         15 . The method of  claim 11 , further comprising:
 forming a third air volume by an enclosure surrounding the lid and the PCB.   
     
     
         16 . The method of  claim 15 , further comprising:
 directing sound waves toward the first port, wherein the sound waves are directed toward the first port through an opening in the enclosure.   
     
     
         17 . The method of  claim 15 , further comprising:
 positioning a mesh between an opening of the enclosure and the second port, wherein the mesh blocks at least one of: debris, foreign material, water ingress, or particulate matter from passing through the second port into the front volume.   
     
     
         18 . The method of  claim 11 , further comprising:
 increasing air volume into the back volume to increase at least one of a sensitivity or a signal-to-noise ratio (SNR) of the MEMS component.   
     
     
         19 . The method of  claim 11 , further comprising:
 incorporating the microphone system into a device, wherein the device is at least one of:   a desktop computer, a notebook computer, a laptop computer, a netbook, a tablet computer, an e-book reader, a Global Positioning System (GPS) device, a camera, a personal digital assistant (PDA), a handheld electronic device, a cellular telephone, a smartphone, a head-mounted device, an augmented reality device, a virtual reality device, a smart watch, or a charging case.   
     
     
         20 . A microphone system comprising:
 a printed circuit board (PCB);   an application-specific integrated circuit (ASIC) attached to the PCB, wherein the ASIC produces a microphone output from an electrical signal;   a micro-electromechanical systems (MEMS) component attached to the PCB, wherein the MEMS component comprises a plate, an acoustic sensor, and a MEMS die substrate, and wherein a front volume of air is formed between the PCB and the acoustic sensor;   a lid secured to the PCB, wherein the lid forms a back volume of air around the ASIC and the MEMS component;   a first port formed in the PCB, wherein the first port is positioned to direct sound waves, through the front volume, toward the acoustic sensor;   a second port formed in the lid to increase air volume into the back volume;   an enclosure surrounding the lid and the PCB, wherein the enclosure comprises an opening to direct the sound waves to the first port; and   a flex securing the enclosure to the PCB.